A fire protection system may comprise a sprinkler system and/or a standpipe system. A sprinkler system is an active fire protection measure that provides adequate pressure and flow to a water distribution piping system, onto which a plurality of fire sprinklers are connected. Each closed-head sprinkler can be triggered once an ambient temperature around the sprinkler reaches a design activation temperature of the individual sprinkler head. In a standard wet-pipe sprinkler system, each sprinkler activates independently when the predetermined heat level is reached. Because of this, the number of sprinklers that operate is limited to only those near the fire, thereby maximizing the available water pressure over the point of fire origin. A standpipe system is another type of fire protection measure consisting of a network of vertical piping installed in strategic locations within a multi-story building for delivering large volumes of water to any floor of the building to supply firefighter's hose lines.
FIG. 1 illustrates a block diagram of a prior art fire protection system 100. The fire pump 102 boosts the water pressure of the water supply by transferring energy to the water. The increase in water pressure acts to move the water into the fire protection system 120. The fire pump controller 108 serves to automatically govern, in some predetermined manner, the starting and stopping of the fire pump driver 102 and to monitor and signal the status and condition of the fire pump unit consisting of a fire pump and driver 102, the controller 108, and accessories. The pressure maintenance pump 106 serves to maintain the pressure on the fire protection system 120 between preset limits when the fire pump is not flowing water. The pressure maintenance pump controller 110 serves to automatically govern, in some pre-determined manner, the starting and stopping of the maintenance pump 106 and to monitor and signal the status and condition of the maintenance pump unit consisting of a maintenance pump and driver 106 and controller 110. Check valves 121 are used in the fire pump installation to allow the flow of water in one direction only for the purpose of building pressure in the fire protection system 120. Check valves are installed between the outlets of each of the pumps and the fire protection system. Gate valves 122 are installed on the inlets and outlets of each of the pumps and are used to isolate either of the two pumps from the fire protection system for maintenance purposes.
The output of this maintenance pump is connected to the system side of the check valve in a typical fire pump installation. The pump's main function is to maintain system water pressure by automatically cycling between pressure set points. That is, the pump will maintain water pressure in the fire protection system by automatically cycling on and off between predetermined, independent START and STOP pressure settings. In this way, the jockey pump functions to make up for small leaks in the system and thereby helps to prevent the larger fire pump from nuisance cycling. Ordinarily, then, the START and STOP settings of the jockey pump are set well above those of the fire pump so that the jockey is cycling to maintain pressure against normal leaks.
The fire pump installation 100 includes a fire pump 102 that is connected to a water supply 104 by way of a gate valve. The water supply 104 provides water flow at a pressure to sprinkler system risers and hose standpipes. Generally, fire pumps are needed when the water supply cannot provide sufficient pressure to meet hydraulic design requirements of the fire sprinkler system. This usually occurs in a building that is tall, such as in high-rise buildings, or in systems that require a relatively high terminal pressure at the fire sprinkler to provide a large volume of water, such as in storage warehouses.
The fire pump 102 starts when a pressure in the fire protection system 120 drops below a certain predetermined start pressure (low pressure). The pressure in the fire protection system 120 may drop significantly when one or more fire sprinklers are exposed to heat above their design temperature, and opens, releasing water. Alternately, fire hose connections to standpipe systems may be opened by firefighters causing a pressure drop in the fire protection system. The fire pump 102 may have a rating between 3 and 3500 horsepower (HP).
The fire pump installation 100 also includes a pressure maintenance pump 106 (also may be referred to herein as a make-up pump or a jockey pump). This pump is intended to maintain pressure in a fire protection system so that the larger fire pump 102 does not need to constantly run. For example, the jockey pump 106 maintains pressure to an artificial level so that the operation of a single fire sprinkler will cause a pressure drop that will be sensed by a fire pump controller 108, causing the fire pump 102 to start. The jockey pump 106 may have a rating between ¼ and 100 horsepower (HP).
The jockey pump 106 may maintain pressure above the pressure settings of the larger fire pump 102, so as to prevent the main fire pump from starting intermittently. For example, the jockey pump 106 provides makeup water pressure for normal leakage within the system (such as packing on valves, seepage at joints, leaks at fire hydrants), and inadvertent use of water from the water supply. When the fire pump 102 starts, a signal may be sent to an alarm system of the building to trigger the fire alarm. Nuisance operation of the fire pump 102 eventually causes fire department intervention. Nuisance operation of the fire pump 102 also increases wear on the main fire pump 102. Thus, it is generally desired to either reduce and/or avoid any nuisance or unintended operation of the fire pump 102.
In the United States, the application of the jockey pump 106 in a fire protection system is provided by NFPA 20: Standard for the Installation of Stationary Pumps for Fire Protection, which prohibits a main fire pump or secondary fire pump from being used as a pressure maintenance pump.
Each of the fire pump 102 and the jockey pump 106 include a pump controller 108 and 110, which may comprise a microprocessor-based controller that can be used to adjust start and stop set points.
As just one example, as early as January 2001, microprocessor-based jockey pump controllers were provided by Firetrol, Inc. of Cary, N.C. These microprocessor-based pump controllers or jockey pump controllers were typically housed in an industrial enclosure, included a digital display and received pressure information by way of a solid state pressure sensor, typically via 1-5 Vdc. Such digital controllers were used to monitor water pressure in the fire protection system, and also allowed user manipulation of certain programmable pumping operations for the control of one, two (duplex) or three (triplex) booster pump systems. Using the electronic pressure monitors, water pressure can be measured with a pressure transducer providing an output of 1-5 Vdc for ranges of 0-300 and 0-600 psi. Operation of the one to three pumps could be independently controlled via programmable digital set points. Such digital set points for each pump include start and stop pressures, and on-delay, minimum run, and off-delay timers. An additional output is provided for a call to start indicating a low pressure condition, and a remote stop/reset input is provided for reset of all timing functions. The digital pressure monitor may be configured for use in simplex, duplex, triplex, and pump up or pump down applications.
The jockey pump controller 110 may have a start pressure set point of approximately five to ten pounds per square inch greater than the start pressure set point in the fire pump controller 108. In this manner, the jockey pump controller 110 cycles the jockey pump 106 to maintain the system at a predetermined pressure well above the start setting of fire pump 102 so that the fire pump only runs when a fire occurs or the jockey pump 106 is overcome by a larger than normal loss in system pressure.
FIG. 2 illustrates a prior art microprocessor based duplex jockey pump controller 200, such as the Firetrol electronic pressure monitor sold under the tradename of “Digital Pressure Monitor FTA470.” This prior art jockey pump controller 200 includes a solid state electronic pressure transducer 202 connected to three analog input pins on the microprocessor controller 204. The pressure transducer measures water pressure and provides an output signal of 1-5 Vdc to the microprocessor controller 204. For example, such solid state pressure transducer could comprise the Model SP975 manufactured by Senso-Metrix. The microprocessor controller 204 outputs a lag pump start/stop signal, a lead pump start/stop signal, and a pump run signal.
The jockey pump controller 200 provides for programmable timing functions, pressure set points, offset and scaling calibration, and pump up and pump down options. Lag and lead pump output signals are provided to energize relays for starting their pumps when pressure drops below a start pressure set point and remain energized until pressure is satisfied at a stop pressure set point. On-delay timers may be programmed in microprocessor controller 200 to provide time delays in starting the pumps upon a call to start (i.e., low pressure). Since these timers are reset if pressure returns to stop pressure, on-delay timers are often used to provide a sincerity check on low pressure for eliminating nuisance starting due to pressure excursions in the fire protection system.
The prior art jockey pump controller 200 further comprises a digital panel display. FIG. 3 is an illustration of the prior art digital panel display that may be used with certain prior art microprocessor jockey pump controllers, such as the controller illustrated in FIG. 1. The digital panel display comprises one or more LED indicators. Such LED indicators could be used for a single digit pump number, a four digit pressure, and a red LED for setup mode, a green LED for run mode, a red LED indicating a call to start (low pressure) in the run mode, a yellow LED indicating on-delay timing sequence in run mode, a yellow LED indicating minimum run timing sequence in the run mode, a yellow LED indicating off-delay timing sequence in the run mode, a green LED indicating stop pressure in the run mode, and a green LED indicating AC power is on. The digital panel display also includes buttons to program the jockey pump controller, such as pump select, mode select, up/down selection arrows, and enter. A second single digit LED display (Pump No.) is provided to indicate which pump is being monitored in a multiple jockey pump installation. A modbus RS 485 serial communications port is provided for the transmission of the pressure value and pressure set points to a master host.
In operation, relays of these prior art electronic digital pressure monitors operate independently based upon an individual start and stop pressure set points. In a system configured for pump up, such as a jockey pump application, the monitor illuminates the “start” LED when system pressure falls below the start set point (low pressure). The pressure monitor energizes the relay to run the first pump provided the on-delay timer is set to zero seconds. If the on-delay timer is set greater than zero, the monitor illuminates the “on delay” LED to start the on-delay timing sequence and delays starting the first pump for the on-delay period. The on-delay timer is immediately reset if pressure becomes satisfied. If the minimum run timer is set to a value greater than zero minutes, the monitor illuminates the “min. run” LED to start the timing sequence and runs the pump for the minimum run period. At the end the minimum run period, the monitor extinguishes the LED and de-energizes the relay to shut off the first pump provided that system pressure is satisfied. Otherwise, the monitor continues running the first pump until pressure is satisfied. If the off-delay timer is set to a value greater than zero minutes, the monitor illuminates the “off-delay” LED to start the off-delay timing sequence after pressure is satisfied. The monitor continues running the pump until the off-delay time expires whereupon the monitor de-energizes the relay to shut off the first pump. Off-delay and minimum run timers are mutually exclusive. To prevent short cycling, a default run time may be used. Additional pumps operate in the same manner with independent start and stop set points.
Although such known prior art microprocessor based controllers offered certain advantages based, in part, on their microprocessor based control, such known prior art microprocessor based devices had certain limitations. For example, one drawback of such early digital microprocessor based jockey pump controllers was that they offered limited ability to help maintenance staff with identifying and potentially diagnosing certain causes of intermittent or frequent maintenance pump cycling. For example, such early microprocessor based devices did not provide a method or manner that would allow the controller to log or store certain operating events. As such, it was often time difficult to identify or trace certain system events that would cause the pump to cycle intermittently or perhaps cause the pump motor and hence the pump to trip off due to certain power or electrical failures. As such, by providing certain data event logging features, it would be beneficial to have certain event logging features that could be user accessible so that certain operating conditions (such as continuous jockey pump cycling or undetermined controller shutdown) relative to jockey pump cycling could be captured for trending and analysis. Such information could also beneficially include controller event information related to how the pump cycles during a certain time of day, during a certain time of week, or even during a defined period of time (e.g., during the first week of a winter holiday). Being able to monitor when and how often such a jockey pump cycles and characterize the jockey pump operating conditions during certain time periods could also prove quite beneficial for correct identification and diagnosis of certain maintenance requirements. For example, early diagnostics of causes of varying pressure levels may reduce the amount of time required to diagnose a potential problem that could prevent a future event causing the fire pump to being cycling and causing nuisance problems associated therewith. In addition, enhanced diagnostics by way of event logging and data tracking may also help identify certain operational concerns that may manifest themselves into a potentially catastrophic fire pump system failure. As such, controller event logging and data tracking may help avoid a costly and undesired downtime of the fire pumping system as a whole. Of course, enhanced diagnostics could also help reduce the amount of time that may be required to bring a fire pump system back on line. Enhanced diagnostics could also help reduce installation time and costs where problems can be quickly identified and resolved.
Another advantage of such data and event tracking would also help the long term function of such a pump system, such as a fire pump system, so that leaks and other causes affecting the jockey pump cycle operation could be efficiently and more easily identified thus increasing the life span of the overall system.
In addition, there is general need for enhanced data communications, particularly in a fire pump system and therefore in the fire pump control room. For example, a jockey pump controller having enhanced digital communications capability could also prove quite useful. For example, such enhanced data communications would allow the controller to communicate in real time certain event history data that it accumulates thus allowing either local or remote communication of this data. That is, maintenance and operational diagnostic information could be communicated remotely to a central location such as a local or a regional maintenance center for fire pump system operational control and maintenance. By providing a jockey pump controller with an enhanced data communications module would allow the controller to communicate via a host of digital communication protocols such as, but not limited to Modbus, Modbus Ethernet, CAN, CANOpen, wireless Ethernet, DeviceNet, ProfiBus, BACNet, ARCNet, ZigBee, Bluetooth, and other similar protocol structures.
In addition, there is also a growing demand for increased record keeping data, data gathering, and storage thereby reducing the overall time and upkeep required to maintain a fire pump system. Also, enhanced record keeping can help trouble shoot certain events that may occur in fire pump systems, such as the system illustrated in FIG. 1.
In addition, in certain critical applications, there is a growing need for three phase voltage monitoring of pumping systems, especially those systems installed on or near weak or unstable power grids. In such critical applications, such voltage monitoring could be used to provide protection against premature equipment and/or pump failure caused by phase reversal. Inadvertent phase reversal in certain critical applications, such as in a fire pump system, could have potentially disastrous consequences where certain pump motors are driven in a reverse direction. In addition, such desired three phase voltage monitoring could also be used to provide protection against phase loss, phase reversal, over or under voltage, unbalanced voltage and short cycling. There is, therefore, a general need for a dependable fault sensing and remote alarm annunciation that can be provided by way of a maintenance pump controller, such as a jockey pump controller. In addition, there is also a demand for remote alarm monitoring of pump fail to start and pump motor overload conditions.